Case-control studies of the aetiological role of occupational exposures, and personal habits including smoking, coffee-drinking and use of artifical sweeteners and analgesics by comparing cases of bladder cancer, cancer of the ureter and cancer of the renal pelvis with controls drawn from the general population as well as matched hospital controls for renal pelvis and ureteral cancer are ongoing. Relative risk estimates as well as attributable risks will be derived for each factor individually. The interaction between factors will be investigated. The final study size will be some 550 cases of bladder cancer, 1100 group matched population controls, and some 150 ureter and pelvis carcinoma-cases to be compared with 450 age- and sex-matched hospital controls. Data collection is estimated to be finished by June 1981.